how to reduce power after enable twi?

[kfcube]

nRF51822

S130

SDK11.0

The power consumption immediately going up high to 1MAH once I enable TWI using this code: 

  NRF_TWI0->ENABLE = TWI_ENABLE_ENABLE_Enabled << TWI_ENABLE_ENABLE_Pos;

Our product requires the power consumption under 0.5MAH at working time. Please help me out here.

I used the twi_hw_master.c from SDK / components/drivers_nrf/twi_master/depreated/twi_hw_master.c

Thanks,
 

[Stian Røed Hafskjold]

Hi, you can disable the TWI from the driver. Please have a look here: https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v11.0.0/hardware_driver_twi.html?cp=7_5_11_2_16_0#hardware_driver_twi_init

[kfcube]

But I do need use TWI. My question is, how to reduce current when using TWI? Thanks,

[Stian Røed Hafskjold]

Hi, you need to stop the transaction after the data is sent, you do not need to uninitialize the TWI driver. This simple example shows how to transmit a single byte, and then stop the transaction. The current will be 1mA during the transaction, and drop down to normal idle current afterwards.

int main(void)
{
    NRF_TWI0->PSELSCL = 2;
    NRF_TWI0->PSELSDA = 1;
    NRF_TWI0->FREQUENCY = 0x01980000;
    NRF_TWI0->ADDRESS = 0x54;
    NRF_TWI0->ENABLE = TWI_ENABLE_ENABLE_Enabled << TWI_ENABLE_ENABLE_Pos;
    NRF_TWI0->TASKS_STARTTX = 1;
    NRF_TWI0->TXD = 0xA1;
    nrf_delay_ms(1000);
    NRF_TWI0->TASKS_STOP =1;
    while (true)
    {
        __WFE();
    }
}